In the feverish search for the missing submersible "Titan" in the Atlantic, there may be a sign of life from the occupants. Search teams registered a type of knocking noise in the region every 30 minutes on Tuesday, where the Oceangate vehicle is suspected to be, according to an internal memo from the US government, from which the broadcaster CNN and the magazine "Rolling Stone" in quoted on Wednesday night (local time).
Additional sonar devices were deployed hours later and the knocking could still be heard. The memo did not specify exactly when and for how long the noise was heard. An update Tuesday night reported additional noises, but these were no longer described as "knocking," according to CNN. However, the sounds indicated that there was still hope for survivors.
The US Coast Guard later tweeted that a Canadian search plane heard "underwater noise". Submersible robots were sent to the area to explore the origin - but initially without success.
Oxygen probably until Thursday noon
Time is pressing: According to estimates by the authorities, the oxygen should only last until Thursday noon (CEST). The conditions are extremely difficult near the "Titanic" wreck about 684 kilometers south of the Canadian island of Newfoundland. It is pitch black and the water pressure is great.
On board the "Titan" is, among others, the French researcher Paul-Henri Nargeolet (77), who is considered one of the best-known experts on the wreck of the luxury liner that sank in 1912 and is therefore nicknamed "Mr. Titanic". Other inmates are British adventurer Hamish Harding (58) and British-Pakistani business consultant Shahzada Dawood (48) and his 19-year-old son Suleman. According to Oceangate, the fifth missing person is the head of the operating company Stockton Rush (61), who acted as the captain of the boat.
The vehicle has been missing since Sunday morning (local time). About an hour and 45 minutes after the start of the dive, which was supposed to last around seven hours, contact with the support boat "Polar Prince" broke off. According to the provider Oceangate Expeditions, the almost seven meter small "Titan" has enough oxygen for a total of 96 hours. But experts were pessimistic about the chance of finding the vehicle in good time and intact.
Meanwhile, executives in the submersible industry have had concerns about Titan's safety for years, according to an article in The New York Times. "We are concerned that Oceangate's current experimental approach could lead to adverse outcomes (ranging from minor to catastrophic)," they wrote in a letter dated 2018 published by the newspaper. It accuses Oceangate of misleading marketing. Boss Stockton Rush was asked to have the "Titan" tested by an independent party.
That fits the impression of reporter David Pogue from the US broadcaster CBS, who took part in the trip last year. He told the BBC the vehicle seemed improvised to him. "You control this submarine with an Xbox game controller," Pogue said. Part of the ballast consists of construction pipes. If the boat gets stuck or leaks, "there's no backup, no escape pod," he said. Former submarine officer Frank Owen told the BBC the biggest challenge for those trapped was staying calm and not using too much oxygen. Search with planes and ships
The search near the "Titanic" wreckage with planes and ships continues tirelessly. Other vessels are en route to the area, including the French research vessel L'Atalante and Canada's HMCS Glace Bay, which has a decompression chamber and medical staff on board. After being rescued, divers who have had an accident must get into such a hyperbaric chamber as quickly as possible in order to prevent permanent damage.
Initially, the search was focused on the water surface by systematically flying over a large area with planes, said John Mauger of the US Coast Guard. Underwater vehicles are said to have arrived by now. The rescue workers mainly used sonar to locate the "Titan". The US Coast Guard said on Twitter that an area of around 26,000 square kilometers had already been searched. That's bigger than Mecklenburg-Western Pomerania.
Navy sends salvage system
Meanwhile, the US Navy is sending a device to salvage the submarine. As a spokeswoman for the German Press Agency said, the "Fadoss" deep-sea salvage system should arrive in St. Johns in Newfoundland, Canada, on Wednesday night (local time) and then be transported further out to sea. The Navy describes it as a "portable ship lift system that provides reliable deep-sea lifting capacity of up to 27 tons for the recovery of large, bulky, and heavy sunken objects such as airplanes or small ships." It can be installed on ships with its winch and rope.
A rescue - whether with "Fadoss" or otherwise - can only be tackled when the boat is located. The wreck of the Titanic, broken in half, lies at a depth of around 3800 meters.
250.000 Dollar pro Person
Oceangate offers wealthy customers an adventurous trip - the cost for the eight-day expedition is around 250,000 US dollars (229,000 euros). The dive itself only lasts a few hours.
The Titanic sank in the North Atlantic in 1912 on her maiden voyage from Southampton to New York. More than 1,500 of the 2,200 people on board died. The remains of the famous luxury liner were discovered in 1985.